Hoist mechanism controls a water passage beside the overflow sill

Hoist mechanism controls a water passage beside the overflow sill. This documentary photograph shows a compact technical building, an operating gantry, a hoist mechanism, a steel gate, a low weir and a rocky forest stream. The scene documents local regulation or diversion of flow by the gate and weir; the actual gate position, discharge and destination of the water are not readable. Composition: Hoist mechanism controls a water passage beside the overflow sill.